fix: Apply proper error caching for SSL certificate failures in TES

- SSL certificate errors (AWSIotException/TLSAuthException) now use UNKNOWN_ERROR_CACHE_IN_MIN (5 minutes) instead of immediate expiry
- Prevents excessive bandwidth usage from continuous retry loops when SSL handshake fails
- Maintains proper error caching behavior for connection failures

This resolves an issue where SSL certificate validation failures would bypass
the intended error caching mechanism, causing credential requests to retry
every ~2 seconds instead of respecting the configured 5-minute cache timeout.

Author: archigup

src/main/java/com/aws/greengrass/tes/CredentialRequestHandler.java

@@ -314,10 +314,11 @@ private byte[] getCredentialsBypassCache() {
             tesCache.get(iotCredentialsPath).expiry = newExpiry;
             tesCache.get(iotCredentialsPath).credentials = response;
         } catch (AWSIotException | TLSAuthException e) {
-            // Http connection error should expire immediately
+            // Http connection error should be cached to avoid excessive retries
             String responseString = "Failed to get connection";
             response = responseString.getBytes(StandardCharsets.UTF_8);
-            newExpiry = Instant.now(clock);
+            // Use unknown error cache policy for SSL/TLS connection errors to prevent excessive retries
+            newExpiry = Instant.now(clock).plus(Duration.ofMinutes(UNKNOWN_ERROR_CACHE_IN_MIN));
             tesCache.get(iotCredentialsPath).responseCode = HttpURLConnection.HTTP_INTERNAL_ERROR;
             tesCache.get(iotCredentialsPath).expiry = newExpiry;
             tesCache.get(iotCredentialsPath).credentials = response;